The present invention relates to an acoustic keyboard musical instrument such as a piano and, more particularly, to a keyboard musical instrument which can simultaneously drive an electronic musical instrument such as an electronic musical synthesizer.
In a recently proposed system, a keyboard musical instrument belonging to an acoustic musical instrument such as a grand piano is connected to another electronic musical instrument to allow simultaneous performance therewith. A conventional system of this type is shown in FIG. 5. Reference numeral 51 in FIG. 5 denotes a grand piano. The grand piano 51 comprises a mechanical vibration sound source designed such that depression of a key is mechanically transmitted by an action mechanism, and that the corresponding hammer is driven to strike the corresponding taut strings, thus producing the musical toner corresponding to the depressed key. The grand piano 51 also comprises a key depression detector for detecting depression of a key. The key depression detector may be a conventional key switch circuit arranged in a conventional electronic musical instrument or a contactless detection device of photo-sensor type which is also known. The key depression detector in the grand piano is connected to an input terminal of a musical tone generator in an electronic keyboard musical instrument (electronic musical instrument) 52 through a cable 53. The electronic keyboard musical instrument 52 is connected to a sound system 54 through a cable 55.
In the grand piano 51, the mechanical vibration sound source produces a musical tone upon depression of a key, and the key depression detector sends a key-on signal corresponding to the depressed key to the electronic keyboard musical instrument 52. The musical tone signal generated by the musical tone generator in the electronic keyboard musical instrument 52 is supplied to the sound system 54. A musical tone is thus produced at the sound system 54. Depression of a key in the grand piano 51 causes sound generation of the mechanical vibration sound source in the grand piano 51 and operation of the electronic keyboard musical instrument 52. In this manner, the grand piano 51 and the electronic keyboard musical instrument 52 can be simultaneously operated by one performer.
In the conventional grand piano 51 as described above, the performer at the grand piano 51 must operate the control switches of the electronic keyboard musical instrument 52 to control the musical tones generated by the sound system 54. When the performer at the grand piano 51 must adjust these control switches, he must interrupt his performance at the grand piano. During the performance, he cannot adjust the musical tone signals generated by the electronic keyboard musical instrument 52. As a result, he undesirably experiences limitations of his musical expressions.